Dental flask



Patented Sept. 29, 1931 UNITED STATES kPATENT OFFICE WALTER J'. CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO COEl LABORATORIES, INC., OF CHICAGO, ILLINOIS, A` CORPORATION i' DENTAL FLASK l@ parts without breaking the investment material. The wax boxing devices of the copending application of Ernest E. Dalton and Charles J. Ringle, Serial No. 224,749, filed October 7,1927, (Patent 1,767,351 granted ,1,5` June 24, 1930), overcomes some of these dif- V liculties butI find that these boxes tend to bulge and even distort under the conipacting and vibration necessary to secure a smooth casting and a dense cast of the investment ma- :la terial.

It is, therefore, one of the objects of my invention to provide an improved dental flask or boxing device so constructed and farranged as to allow the easy removal of the investment and at the same time capable of withstanding considerable compression and vibration. Another object of my invention is to provide a boxing device wherein the parts may be formed of metal and, when opening, are directly pulled away from the investment plaster, instead ofsliding the partsL along the plaster as is common among the metal dental flasks with which I am familiar. A still further object of my invention is to provide a metal boxing device or dental flask wherein the parts may be securely locked in closed position and Which, when opened', are adapted to bemoved directly away from the investment plaster. Another object is to provide for obtaining a positive separation of the parts of the boxing device inopening the same not only from each other but from the enclosed investment material.

Other objects and advantages of my invention will appear to those skilled in the art after a consideration of the'following description, taken in conjunction' with the accompanying drawings, in which:

Figure 1 is a top plan view of my improved boxing device.

Figure 2 is a sectional view taken on the line .2 2 of Figure 1.

Figure 3 is a view, partly in section, and partly 1n elevation, taken on the line 3-3 of Figure 2. l

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a fragmentary bottom view howing how the false bottom is held in the In the drawings the numeral 1 indicates a modelrof plaster-like material, usually made from the dentists impression, which carries the wax pattern 2 and has the sprue 3 and sprue leads .4.

The plaster model 1 is adapted to be placed upon a false bottom 5 having upstanding nubs or projections 6 which support the plaster model, permittingit to be entirely surrounded by-investment. The false bottom 5 is provided with a'dependingfscrew head 7 ltoy which it is held securely in its proper posilon. e v

TheV numeral 8- designates, as a whole, my novel boxing device or dental flask which is seen to consist of a metal body split into two parts 9 and 10.v Each part is provided with a forwardly extending handle, designated by the numerals 11 and 12 in Figure 1, and rearwardly extending apertured lugs 13. A hinge pin 14 extends through the apertured lugs 13, the pin and lugs cooperating to hingedly connect the parts 9 and 10 together whereby the handles may be actuated to open or close the boxing device. The hinge pin 14 is extended upwardly a substantial amount, as shown in Figure 2, for a purpose to be hereinafter described.

The handle 11 is rigidly secured to the part 10, or may be cast integrally therewith, while Vthe handle 12 is hinged to the part 9, as shown 'in Figure 1, the part 9 having a pair of forwardly extending apertured lugs 15 which receive a pin 16 which hingedly carries the handle 12. The hinged handle 12 is provided lwith a hook portion 17 having a cam surface '18 which is adapted to engage a projection 19 on the handle 11 when the handles are brought together as shown in the full line position in Figure 1, whereby the two parts 9 and 10 are held locked in closed position. rllhe inner end of t-he handle 12 is extended inwardly to form a cam 20 which, when the handle 12 is moved from the full line position to the dotted line position shown in Figure 1, is adapted to bear against thefrigid handle 11 and to thereby cam open the two parts 9 and 10, moving them about the hinge pin 14. It will be observed that the lugs are of suihcient length to space thehinge pin 14 a substantial distance away from the sides of the parts 9 and 10. Thus it is that when the element 20 is actuated to cam open the two parts 9 and 10 they are moved directly away from the casting 21 of investment material surroundingthe plaster model.

The cover for my dental flask is seen to consist of two mating sections hinged together, as by a pin or screw 24 passing through rearwardly extending lugs 25 and 26 mounted respectively on the two halves of the cover, the lugs 25 and 26 being apertured for the reception of the pin or screw 24. The cover members 22 and 23 are provided with forwardly extending projections 25 and 26 which are received between two forwardly and upwardly extending abutments 27 and 28 respectively, mounted on or formed as a part of' the two parts 9 and 1() of the dental flask 8. The rearwardly extending lugs 25 and 26 of the cover halves are each `notched so as to form a slot 29 when in closed position forreceiving the upwardly extended portion of the hinge pin 14, as shown in Figure 2. The cover halves are provided with upstanding portions 32 and 33 which form, when the cover halves are closed, a tubular projection. Each meeting edge of the bottom of the parts 9 and 10 is provided with a semi-circular notch adapted, when these parts 9 and 10 are closed, to embrace the screw head 7 to thereby hold the false bottom 5 in position, as described above.

In operation, the cover halves are first removed and the vhandles 11 and 12 moved to close and lock these parts 9 and 10 together, the false bottom 5 having rst been placed in the proper position in the box 8. Model 1 is now set into box 8, resting on nubs or projections 6. v

Next the investment plaster is introduced around the model and pattern up to the top edge of the parts 9 and 10, it being understood that during such operation the boxing device may be vibrated in any known manner, as by tapping it against a stationary object or holding it against some vibrating element, the handle means 11 and 12 enabling my boxing device to beeasily handled while being vibrated. e

Due to the fact that the box is formed of metal it can be vibrated to a greater extent than in the case of wax boxes, thereby producing a denser investment and one in which there is little likelihood of entrained bubbles of air remaining.

As the investment is built up, in the foregoing manner to or toward the top of the box 8 the cover halves 22 and 23 are placed in position. The upright tubular' projection formed by the portions 32 and 33 in addition to providing for introducing further investment material and for additionally compacting the same receives the sprue 3 formed on sprue 'leads 4 of the wax pattern 1. Then the boxing device has been filled to the top of thetubular projection, the investment in the boxing device-may be additionally compacted by further vibration.

` When the cast of investment plaster has hardened the same is removed from the flask 8 by rocking the handle 12 to the position shown in dotted lines in Figure 1, thereby camming open the parts 9 and 10, as shown in Figure 5, and moving them directly away from the cast. Following this the parts 9 and 10 may be turned by hand to a wider position and the cast lifted from the box 8, the initial separating movement of the parts 9 and 10 serving to break loose and free the cast if there is any tendency to stick to the sides of the box 8. The halves of the cover member are separated by inserting a tool in the notch 36 formed in the lugs 27 and 28 thereby prying the halves apart. The cover and false bottom are pryed loose with any suitable flat blade.

Obviously many modifications may be suggested to those skilled in the art and I do not intend to be limited to the specific embodiment shown in the drawings.

I claim:

1. A kdental flask comprising the combination of a box formed in two separable sections, means hingedly connecting the sections together, handle means for said sections, a bottom plate, cooperating means on said plate and said sections for fixing said plate in position when the sections are closed, cover means for said box, and locking means actuated by one ofV said handles 'for holding the sections in closed position.

2. A dental flask comprising the combination of a box formed in two separable sections, means hingedly connecting the sections together, handle means for said sections, a bottom plate, cooperating means on said plate and said sections for fixing said plate in position when the sections are closed, cover means for said box and comprising a pair of cover sections hinged together, and locking means actuated by one of said handles for holding the sections in closed position.

3. A dental flask comprising the combination of a box formed in two separable sections, means hingedly connecting the sections together, said means including apertured lugs carried by said sections and extending rearwardly therefrom and in spaced relation thereto, handle means for said sections, a bottom plate, cooperating mea-ns on said plate and said sections for iixing said plate in position when theV sections are closed, cover means for said box and comprising a pair of cover sections hinged together, and locking means actuated by one of said handles for holding the sections in closed position.

1l. A dental Hash comprising a box formed in two separable sections, hinge means for hingedly securing the sections together, cover means for said sections, said cover means comprising separable sections, means mounting the cover on the box, and cooperating means on the box and cover for holding the sections of the cover together when the box sections are closed.

5. A dental iask comprising a box formed in two separable sections, hinge means for hingedly securing the sections together, handles carried by each section, and cover means for said box, said cover means being formed of two parts hingedly secured together, each part having a forwardly extending lug, each of the sections having an abutment member, said members being adapted to hold said cover closed when the said sections are closed.

6. A dental flask as defined in claim 5 and in which the lugs of the cover have slanting portions forming a notch.

7. A dental flask comprising a box formed in two separable sections, said box having hinge means hingedly securing the sections together, and handle means carried by each section, said handle means including a handle member rigidly carried by one section, a second handle member hinged to the other section and having a hook adapted to engage a projection formed on the first mentioned handle member when the sections are closed whereby they are locked in closed positions.

8. A dental flask comprising a box formed hinge means hingedly securing the sections 11. A 'dental flask comprising a box formed in two separable sections, said box having hinge means hingedly securing the sections together, handle means carried by each section, saidhandle meansl including a handle member rigidly carried by one section and a second handle member pivoted to the other section, said pivoted handle having limited movement in one direction and free movement in another direction withrespect to said other section, whereby the pivoted handle is operative in one position to hold the sections closed and is operative when moved in said other direction to separate the sections.

In witness whereof, I have hereunto subscribed my name this 26th day of Sept., 1929.

WALTER J. CLARK.

in two separable sections, said box having hinge means hingedly securing the sections together, and handle means carried by each section, said handle means including a handle member rigidly carried by one section and a second handle member hinged to the other section, the hinged handle member having an'inwardly disposed extension adapted, when the hinged handle is turned, to bear against the rigid handle to initially separate the box sections.

9. A dental iask comprising a metal box formed in two separable sections, said box having hinge means securing the sections together, handles on each section, one of said handles being hinged to one of the sections and having a projection forming a cam surface adapted to bear against the handle of the other section to impart a separating movement to the sections when the hinged handle is turned.

l0. A dental flask comprising a box formed in two separable sections, said box having 

